From 2cf938aae17203426a89b5955bd1c9668657bfa8 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Thu, 17 Mar 2016 14:22:03 -0700 Subject: mm: use radix_tree_iter_retry() Instead of a 'goto restart', we can now use radix_tree_iter_retry() to restart from our current position. This will make a difference when there are more ways to happen across an indirect pointer. And it eliminates some confusing gotos. [vbabka@suse.cz: remove now-obsolete-and-misleading comment] Signed-off-by: Matthew Wilcox Cc: Hugh Dickins Cc: Konstantin Khlebnikov Signed-off-by: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/shmem.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) (limited to 'mm/shmem.c') diff --git a/mm/shmem.c b/mm/shmem.c index c484f6888d5e..91c0dadf48d3 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -383,13 +383,10 @@ restart: page = radix_tree_deref_slot(slot); - /* - * This should only be possible to happen at index 0, so we - * don't need to reset the counter, nor do we risk infinite - * restarts. - */ - if (radix_tree_deref_retry(page)) - goto restart; + if (radix_tree_deref_retry(page)) { + slot = radix_tree_iter_retry(&iter); + continue; + } if (radix_tree_exceptional_entry(page)) swapped++; @@ -1951,8 +1948,10 @@ restart: radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) { page = radix_tree_deref_slot(slot); if (!page || radix_tree_exception(page)) { - if (radix_tree_deref_retry(page)) - goto restart; + if (radix_tree_deref_retry(page)) { + slot = radix_tree_iter_retry(&iter); + continue; + } } else if (page_count(page) - page_mapcount(page) > 1) { spin_lock_irq(&mapping->tree_lock); radix_tree_tag_set(&mapping->page_tree, iter.index, @@ -2006,8 +2005,10 @@ restart: page = radix_tree_deref_slot(slot); if (radix_tree_exception(page)) { - if (radix_tree_deref_retry(page)) - goto restart; + if (radix_tree_deref_retry(page)) { + slot = radix_tree_iter_retry(&iter); + continue; + } page = NULL; } -- cgit v1.2.3